Sexual Reproduction in Flowering Plants
Quiz-19
Dear Readers,
NEET is the most famous and important medical entrance examination held in our country. This exam is an objective type, an offline test which includes 4 sections namely– Physics, Chemistry, Botany, and Zoology. The maximum marks that can be scored are 720 marks and have 180 questions.
About half of the paper consists of questions from Biology, as the NEET exam essentially focuses on capacitating students to go for seats in medical courses. One of the most significant and crucial sections in the NEET exam is of Biology. It comprises of theories, descriptions, discoveries, diagrams, definitions, explanations of differences, and relations. The majority of the topics covered in the NEET syllabus are from the NCERT syllabus of Class 11 & 12 and other related sources become part of the rest of the syllabus.
Clear Exam curates a list of articles selected by professionals who recommend the highly vital topics for NEET exams. The table below takes you directly to the respective topic where the in-depth article and the MCQs are available for an easy and productive learning experience. Prior to solving NEET question papers or practicing mock tests, you must ensure to study the basic concepts in NEET and practice a few sample questions related to this exam. Students will be covered for all their studies as the topics are available from basics to even the most advanced.
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Q1. Megaspore mother cell is found near the region of
Solution
Ovules generally differentiate a single Megaspore Mother Cell (MMC) in the micropylar region of the undifferentiated tissue (nucellus). It is a large cell containing dense cytoplasm and prominent nucleus. The MMC undergoes meiotic division.
Ovules generally differentiate a single Megaspore Mother Cell (MMC) in the micropylar region of the undifferentiated tissue (nucellus). It is a large cell containing dense cytoplasm and prominent nucleus. The MMC undergoes meiotic division.
Q2.Identify different ovules of diagrams A to F
Solution
A-Orthotropous It is also called atropous. It is erect no bending is there, e.g., Polygonum B-Anatropous Completely inverted, e.g., Helianthus C-Hemitropous The micropyle and chalaza line at 90° to funicle, e.g., Ranunculus D-Campylotropous more curvature than hemitropous, e.g., Capparis, mustard E-Amphitropous Horse shoe like,e.g., Capsella F-Circinotropous Ovule straight micropyle upward due to unilateral growth of funicle it become inverted, e.g.,Opuntia.
A-Orthotropous It is also called atropous. It is erect no bending is there, e.g., Polygonum B-Anatropous Completely inverted, e.g., Helianthus C-Hemitropous The micropyle and chalaza line at 90° to funicle, e.g., Ranunculus D-Campylotropous more curvature than hemitropous, e.g., Capparis, mustard E-Amphitropous Horse shoe like,e.g., Capsella F-Circinotropous Ovule straight micropyle upward due to unilateral growth of funicle it become inverted, e.g.,Opuntia.
Q3. An angiospermic leaf carries 16 chromosomes. The number of chromosomes in its endosperm will be
Solution
A somatic cell (e.g., cell of leaf) contains diploid number of chromosomes. In angiosperms, the endosperm is formed by triple fusion, i.e., fusion of two polar nuclei and second male gamete. Therefore, it is triploid (3n). Hence, the chromosome number in endosperm will be =24.
A somatic cell (e.g., cell of leaf) contains diploid number of chromosomes. In angiosperms, the endosperm is formed by triple fusion, i.e., fusion of two polar nuclei and second male gamete. Therefore, it is triploid (3n). Hence, the chromosome number in endosperm will be =24.
Q4. Study the following pairs.
I. Modified - Unisexual - Chalazal
aerial stem flowers entry of
Develop pollen tube
Acropetally
II. Flowers - Pedicels of all - Presence of
achlamydeous the flowers false whorl
are of same
Length
III. Cohesion of - Centrifugal - Male flowers
Bracts opening of many
forming a cup flowers
IV. flower - Presence of - terminal part
Formation on rachilla of the peduncle
One side in a is flowerless
Spiral manner
Select the correct pair of answers in which the former represents the set of characters present in
poinsettia and the latter in the pair represents the set of characters present in casuarina.
Solution
In Poinsettia and Euphorbia, inflorescence is cyathium, in which involucre fuse to form a cup surrounding a large achlamydous, pedicellate, tricarpellary, syncarpous female flower. Numerous centrifugally arranged male flowers surround the female flower.numerous centrifugally arranged male flowers surround the female flower. In Casuarina,cylindrical phylloclades are found which are modified aerial stems. Flowers are unisexual which develop acropetally and pollen tube enters the ovule through chalazal tissues,i.e., chalazogamy.
In Poinsettia and Euphorbia, inflorescence is cyathium, in which involucre fuse to form a cup surrounding a large achlamydous, pedicellate, tricarpellary, syncarpous female flower. Numerous centrifugally arranged male flowers surround the female flower.numerous centrifugally arranged male flowers surround the female flower. In Casuarina,cylindrical phylloclades are found which are modified aerial stems. Flowers are unisexual which develop acropetally and pollen tube enters the ovule through chalazal tissues,i.e., chalazogamy.
Q5.There are 10 flowers in one individual plant of crotalaria. In each microsporangium of every stamen of all the flowers, there are 30 microspore mother cells. How many pollen grains are formed from that plant?
Solution
Crotalaria is a member of Papilionaceae (Fabacese), in which 10 stamens are present in a (d) Crotalaria is a member of Papilionaceae (Fabacese), in which 10 stamens are present in a flower. Each stamen has four microsporangia, in which microspore mother cells are found. Each microspore mother cell gives rise to a pollen tetrad. Thus, 10 flowers (with 10 stamens in each) having 30 microsporangia in each microsporangium will form 48,000 pollen grains.
Crotalaria is a member of Papilionaceae (Fabacese), in which 10 stamens are present in a (d) Crotalaria is a member of Papilionaceae (Fabacese), in which 10 stamens are present in a flower. Each stamen has four microsporangia, in which microspore mother cells are found. Each microspore mother cell gives rise to a pollen tetrad. Thus, 10 flowers (with 10 stamens in each) having 30 microsporangia in each microsporangium will form 48,000 pollen grains.
Q6. Viability of date palm seed is
Solution
Viability of datepalm is 2000 yr.
Viability of datepalm is 2000 yr.
Q7. Type of pollination in commelina is
Solution
Cleistogamous flowers never open and in them only self-pollination is operated. In Commelina benghalensis (kankauoa), the underground flowers are cleistogamous, in which Cleistogamy (a type of self-pollination) occurs.
Cleistogamous flowers never open and in them only self-pollination is operated. In Commelina benghalensis (kankauoa), the underground flowers are cleistogamous, in which Cleistogamy (a type of self-pollination) occurs.
Q8. The function innermost layer of pollen sac, tapetum is
Solution
Tapetum is the innermost layer of the wall of pollen sac. Tapetum cells are nutritive in function.
Tapetum is the innermost layer of the wall of pollen sac. Tapetum cells are nutritive in function.
Q9. Larger nucleus in a pollen grain is
Solution
Pollen grain is the mother cell of male gametophyte. Development of male gametophyte begins inside the micro sporangium. The microspore nucleus divide mitotically to form a smaller generative cell and a much large, vegetative cell (tube cell) the generative cell produces two male gametes, whereas, the vegetative cell form pollen tube after pollination. Pollen grain contains two cells, i.e, tube cell and generative cell at the time of pollination.
Pollen grain is the mother cell of male gametophyte. Development of male gametophyte begins inside the micro sporangium. The microspore nucleus divide mitotically to form a smaller generative cell and a much large, vegetative cell (tube cell) the generative cell produces two male gametes, whereas, the vegetative cell form pollen tube after pollination. Pollen grain contains two cells, i.e, tube cell and generative cell at the time of pollination.
Q10. Pollens are considered as well preserved fossils due to the presence of
Solution
Pollens are well preserved because the sporopollenin. It is hard and resistable to many organic and inorganic compounds.
Pollens are well preserved because the sporopollenin. It is hard and resistable to many organic and inorganic compounds.
